Efficient Way of Carbon Dioxide Utilization in a Gas-to-Methanol Process: From Fundamental Research to Industrial Demonstration

Efficient utilization of CO 2 to produce clean liquid fuels and various petrochemicals has attracted significant attention during the past decades. This review mainly focuses on our efforts and main achievements during the development of a CO 2 -utilizing Gas-to-Methanol (CGTM) process, which is composed of CO 2 /steam-mixed reforming and methanol synthesis via CO 2 and CO hydrogenation. Experimental apparatus at different scales, ranging from lab to demonstration, have been established to pursue an efficient CGTM process with enhanced energy efficiency and reduced CO 2 emissions. The proposed CGTM process employs a proprietary coke-resistant Ni-based catalyst in the reforming section, which is very stable under a 1000-h accelerated stability test. Based on the results of the process simulation and optimization obtained by using Aspen Plus, a CGTM demonstration plant with a methanol-production capacity of 10 t/day is designed and constructed, which comprises a reforming section (co-feeding CO 2 into the reformer), a methanol synthesis section, and a recycling section. During the continuous operation for 1000 h, the CGTM demonstration plant exhibited a satisfactory performance, which is in good agreement with the design values. The overall thermal efficiency is shown to be superior to that of the conventional Gas-to-Methanol (GTM) processes, and the CGTM process is economically feasible given that the NG price, methanol price, and the plant scale are located in the following range of 1–5 $/MMBTU, 350–500 $/Mt, and 2500–5000 TPD, respectively. Furthermore, the proposed CGTM process would be even more competitive in the case of a higher carbon tax.